Telephone system.



G. S. WINSTON.

TELEPHONE SYSTEM. APPLICATION FILED NOV. 1, 1912.

Patented Sept. 29, 1914.

. J2; i/E 27 7271". [551755 in STATES PATENT orrion.

CHARLES S. WINSTON, OF CHICAGO, ILLINOIS, ASSIGNOB. 'IO KELLOGG SWITCHBOARD AND SUPPLY COMPANY, OF GHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

' TELEPHONE SYSTEM.

Srpecifi'cation ofiLetters Patent.

Patented Sept. 29, 1914.

Application filed November 1, 19.12.. Serial No; 729,076.

To all whom itmay concern:

Be it known that 1 CHAnLnsS: Winston, a citizen of the United States, residing in Chicago, county of Cook, and State'of 111i nois, have invented certain new and useful Improvements in Telephone Systems, of which the following. is-a specification.

My invention relates to telephone systems and has to do more particularly with cir cuits involved in interconnecting magneto andcommonbattery lines, an= obj ect'being" to provide an improved circuit arrangement which is more simple and positivein operation.

In the magneto line telephone systems which are being installed at thepresent period, lamp signals are coming into general use, and one of the features of my invention .is to provide nnproved circuit arrangements in which mechanical locking supervisory re lays are employed which may be controlled from a connected magneto line orthrough the medium of a trunk circuit from aconnected common battery line.

Referring now to the accompanying drawing, 1 have illustrated a circuit arrangement adapted'forinterconnecting magneto or magneto and commonbattery lines, said arrangement comprising a'ma'gneto telephone A connected by a lineB with a central office-terminal C. The cord circuit .D isadapted for interconnecting the magneto lines B or connecting a magneto line B- through the medium of a trunk circuit E' to a common battery line circuit F connected by a line G to common battery telephone H. For the purpose of illustration, we will assume an exchange with a plurality of magneto-lines B terminating at a switchboard equipped with cord circuits D and a plurality of trunk jacks J terminating at the magneto switchboard and connectedto a trunk E terminating in plugs P? at a eommonbattery' switchboard having a plurality of'common battery lines G terminating thereat.

Referring-now more in detail to the apparatus involved in the system illustrated, the substation A is of a well known magneto or local battery type connected byline conductors B to a jack j at thecentral ofiice, said jack having a signal' 2' connected in circuit therewith and in bridge of the line conductors.

The magneto operators cord circuit D comprises answering and calling plugs 1Ev and P respectively, said plugs being connectedlby the talking strands 3 and 4 having condensers 5- and 6 interposed therein. A ringing key K is connected with the calling plug. 13 and is adaptedto connect the ringing'generator 7 and. ground 8 to the tip and ring terminals of the'plug; A so called ring back; key K is similarly connected to the answering plug P. A supervisory trip relay as M is associated with eachend of the cord circuit',.which: relay comprises two cooperating electromagnets 9 and 10. Magnet 9 is adapted whenenergized to attract its armature'll, whereby said armature moves to trip thecontact spring 12, allowing it to move downwardly and into connection with its alternate grounded contact. It will be seen that with armature-11 attracted, due to the tripping'of spring 12, of over the armature 11, although magnet 9 may be denergized, the alternate contact 12 remains-closed. To-restore contact 12, magnet 10 is energized, attracting its armature 13, whereby the insulated connection-extending to contact 12, raises the,saidcontact 12 clear of the armature 11 allowing the retraction thereof, and thereafter when electromagnet. 10 isdeenergized, retracting its armature 13, spring'12rests upon armature 11 maintaining contact 12- interrupted. Supervisory signals 14' and 1'5 are provided for the answering and=calling ends, respectively, of" the cord circuit D, being displayed by energization of either one of the associated relays-9 or 10. Listening key LK is adapted when actuated to connect the operators telephone circuit 0* across the talking strands of cord circuit D, said key LK also having contact springs 21 which are closed when .key LK is operated, tooperate the restoring magnet-s 10 and 10. Branch circuits 1 and 1 extend from relays-10, 10 respectively, to the'third contact of the associated plug, as an alternate operating circuit for these relays when connection is made to a trunk circuit E.

Trunk circuit E comprises a trunk jack J having a trip contact 16, a ring contact 17 and a third or sleeve contact 18. The tip and rin contacts of jack J are connected by the heavily marked talking'condnctors through the windings of a repeating coil RC the calling plug P. A sleeve supervisory relay SR is connected to the so-called sleeve talking strand of the trunk circuit E, and a tip supervisory relay TS is connected to the tip talking strand. An auxiliary tip'supervisory relay TS is connected to the tip relay S and is adapted to be energized during 5 energization of the tip relay. Relays TS and TS might be combined as a single relay, but are arranged in the manner shown'to due to being operated by current over the called telephone line. A combined guard and supervisory lamp signal 19 is provided for trunk circuit E, being controlled through contacts of the supervisory relay SR and jack contacts 20,, and also by guard relay GR.- A ringing relay RR is provided for connecting ringing current from generator 22, said -relaybeing preferably controlled from the originating operator at cord circuit D, the control of RR being preferably 20 by the operation of key K which connects ground to the sleeve talking strand and through the winding of RR to battery. An operators telephone circuit 0 is provided for trunk circuit E being connected by means of an order wire to the operators at the magneto switchboard having access to trunk circuits E.

The common battery line circuit F is of a well known type, comprising a line relay so LR, cut-01f relay G0, a line lamp Land multiple jacks J and the common battery substation H is also of the well known Kellogg type.

Operation: Assuming now the subscriber at A desires to communicate with a subscriber at substation. H, he will operate his hand generator thereby throwing the drop 2 at the central station, whereupon the operator inserts an answering plug P into the 40 jack 7', and then throws her listening key K to ascertain the wants of the calling subscriber. Upon finding that the wanted substation is a common battery line terminating at a distant switchboard for example, she communicates by means of an order wire to the operators telephone 0 of a trunk operator. The trunk operator then replies designating the number of the trunk to be used,'and having ascertained the number of the called line, tests the wanted line and finding it idle, inserts the answering plug P into a jack J thereof. The act of inserting the plug P connects supervisory relay SR and cut-off relay CO in series circuit over the sleeve talking conductor,

whereby said relays are energized, the energization of CO afi'ecting theclosure of its alternate contacts 24, 25, thereby extending the connection from the talking strands of link circuit E to the line conductors G and substation H. The local operator at cord circuit D inserts the calling plug P into the jack J of the selected trunk *E, thus establishing a circuit over the third conductor of $5 the plug and jack including relay 10 and provide a more sensitive control guard relay GR. This circuit may be traced trom battery through the winding of relay 10 the branch conductor 1 and third contact 27 of plug P third contact 18 of jack J, winding of GR to ground at normal contact 28. Relay 10 is therefore energized establishing a circuit for supervisory signal 15 which remains lighted until the called subscriber responds as will be further described. The energization of guard relay GR resulting from the previously traced circuit has no effect unless the trunk op erator has picked up a plug P of a-trunk different from that into which the magneto operator has inserted plug P For instance should the magneto operator insert the plug into the wrong jack J, guard relay GR will be energized as described and due to the fact that the sleeve relay SR of this trunk is not energized a circuit for lamp 19 will be established from battery through said lamp, normal contact 42, alternate contact 39, to ground at normal contact 28. The operator observing this signal will know that the wrong trunk has been plugged into. Furthermore if the trunk operator has picked up the wrong lug P and inserted it in a jack J relay S R is energized, closing alternate contact 42 and thereby establishing a circuit for lamp 19 to ground at contacts20 of jack J.

. From the above it will be seen that unless the trunk E is connected to at both ends, lamp 19 will be lighted as a guard signal.

In the present embodiment of my invention I have preferably arranged the ringing of distant called substations to be controlled b the originating operator. Therefore, after the operator inserts theplug-P, she throws ringing key K, connecting generator 7 to the tip strand, which causes ringing current to flow through a winding of the repeating coil RC, normal contact 38 and impedance coil 30 to ground. This circuit is of no purpose, but the impedance coil 30 is provided as a path for current from generator 7 so that no bad inductive effect is produced in the cables of the switchboard which might result if no path for current from generator 7 were provided. The connecting of ground 8 by key K, afi'ects the operation of ringing relay RR, this circuit being traced from said ground 8, contacts 31, 17, a Winding of repeating coil RC, normal contact 32, alternate contact 35, and the winding of RR to battery. Upon each operation of ringing-key K, ringing relay RR is thus operated, closing its alternate contacts 36, 37, thereby connecting ringing generator 22 in bridge of the called line.

The subscriber at substation H in response to the call removes the receiver thereat, whereby a circuit for tip supervisory relay TS is provided, traced from ground through the winding of TS, alternate contact 40, nortalking strands mal contact 36, tip contacts of plug and jack, alternate contact 124, the line G and substation H, alternate contact 25, sleeve contacts of jack and plug, :and thewinding of SE to battery. Relay TS therefore energizes, closing its alternate contact 28, and establishing a circuit for TS causing it to energize and lose the talking circuit through its alternate contact '38 and in'te-rrupting the ringing normal contact '82. The energization of TS also interru ts the circuit for relay GR, and relay 10 '0 cord circuit D, whereby :a'lternate contact 13 of relay 10 is restored effacing -supervisory signal 15 .and indicating to the originating operator that "the called subscriber :has responded. Alter completing -conversation,-the subscriber at A gives his hand generator a ring-off operation and magnet 9 being connected in bridge of the of the-cord circuit and line, is operated to-at-tract its armature 11 whereby alternate contact '12 is closed establishing a circuit for supervisory signal 14. The subscriber at H upon replacing his receiver, interrupts the circuit for relay TS, which deenergizes, interrupting'thecircuit :for' TS, which also restores. contact '28 at T8 reestablishes the series circuit through relay GR and relay "10 ofcord circuit D, whereby these relays are energized, the energization of 10 effecting an operation of signal 15 whilev the operation of GR is at this time only incidental.

The operator-at D observing the two disconnect signals 14 and '15, withdraws plugs P and P jfrom their engaged spring jacks and also throws 'her listening key LK to close alternate contacts 21 thereof. The closing of-these contacts 21 establishes en ergizing circuits for relays 10 and 10 whereupon relay 10 energizes, lifting the contact 12 clear of armature 11, allowing said armature to restore and holding contact 12 open. The energization of 10 by the key operation in this instance is unnecessary as it will be remembered magnet 9 wasnot operated. Upon restoration of-key LK, the circuits for magnets 10 and 10 are interrupted, allowing said magnets to restore. The withdrawal 'of plug P from jack J causes the closing of contact 20 of jack J and a circuit is therefore established-for supervisory lamp 19 through alternate contact 42, is still energized. The trunk operator observing signal 19, withdrawsplug P from its connected jack, whereby the circuit for SR being interrupted it restores interrupting the circuit for signal 19. Cut-oft relay CO having restored, all of the apparatus is again at normal and available for use in establishing other connections.

7 Assuming now that the subscriber at A has signaled the operator and desires con- :control circuit .at its- Jbridged electromagnet-s 9, 9 tion of these magnets trips their associated The closing of :normal as it will be remembered that SR connection znection with another magneto telephone line,

the operator after having inserted plug P in the jack of calling :line B, inserts plug '15 into a jack j of the called line. This last operation of course disconnects the bridged -.drop signal :2 and the operator thereupon through key 'Kconnects ringing generator 7 inzbridge of the called line to signal the called substation. After the subscribers have finishedtheir'rconversation they restore their receivers-upon their respective switchhooks also-giving a ring-off operation to their hand generators and thereby energizing the The operacontacts 12, "12 effecting the operation of supervisory-signals 14, 15. The operator observing these signals withdraws plugs P and P and upon throwing listeningkey 'LK cont-acts'21iare closed establishing an energizingcircuit :for magnets 10 and 10 whereby the springs 12, 12 =are lifted to interrupt their contacts and allow restoration of the armatures 1'1, 11 ,respectively.

Itwlill be apparent that many changes to the circuit arrangement will readily suggest themselves and therefore 'I do notdesire to be limited to the exact system. as shown and described,'but aim to cover all-those changes 'and -modifications as come within the spirit and scopeof the appended claims.

What I claim as newand desire to secure by United States Letters Patentis:

1. A telephone system comprising magneto and commonbattery lines, a cord circuit connected to a magneto line, a. trunk. circuit interconnectin said cord circuit and a common battery l1ne,-a pair of talking conductors included in the connection extending between said lines, a supervisory relay for the cord circuit, a supervisory relay for the trunk circuit included in circuit with and controlled over the called line, and a circuit connection including the windin of said cord supervisory relay, normally c osed com '110 =tacts on said trunk relay and a third conductor between said cord and link circuits. 2. A. telephone system comprising magneto and common battery lines, a cord circuit for directly interconnecting the magnetolines and connected to a calling one of them,

a trunk circuit interconnecting said cord circuit and a common battery called line, a pair of talking conductors included in the extending between said line, an 1?.0 answering supervisory relay for the cord circuit, an-answering supervisory relay for :the trunk circuit, and a control circuit for the cord supervisory relay independent of said talking conductors and including normally closed contacts of the trunk supervisory relay and a third conductor between said cord and trunk circuits.

3. A cord circuit comprising in pair of three conductor connecting terminals, a pair of talking conductors extending between two of the conductors of said connectin terminals, a relay at each end of said cor circuit having a winding connected in bridge of said conductors, a second relay at each end of the cord circuit connected to the third conductor of the corresponding terminal, a signal common to the pair of relays at each end of the cord circuit, and circuit connections extending from said signal to contacts on each of said relays, each circuit being adapted for independently displaying the associated signal.

4. A telephone system comprising magneto and common battery lines, a cord circuit connected at its answering end to a magneto line;a trunk circuit connected to the calling end of the cord circuit and adapted for extending the connection to a common battery line, a pair of talking conductors included in the connection between said cord and trunk circuits, a supervisory relay for the cord circuit, a guard signal relay for the link circuit, and a series operating circuit for said relaysclosed when said cord is connected to the trunk and including a third conductor between said cord and trunk circuits.

5. A telephone system comprising magneto and common battery lines, a cord circuit connected at its answering end to a magneto line, a trunk circuit connected to the calling end of the cord circuit and adapted for extending the connection to a common battery line, a pair of talking conductors included in the connection between said cord and trunk circuits, a supervisory relay for the cord circuit, a guard signal relay for the link circuit, a series energizing circuit for said relays closed when said cord is connected to the trunk and including a third conductor between said cord and trunk circuit, and a guard signal for said trunk having an operating circuit including contacts of the guard relay said circuit being adapted to be closed if the cord is connected to the trunk before the trunk is connected to a called common battery line.

6. A telephone system comprising magneto and common batter linw, a cord circuit, a trunk circuit, said cord circuit being adapted for directly interconnecting the magneto lines or for use in connection with the trunk circuit for interconnecting calling magneto and called common battery lines, a pair of talking conductors for said cord circuit, a supervisory relay in bridge of said conductors for use when said cord is interconnecting magneto lines, a second supervisory relay for said cord connected to a third conductor extending to said trunk circuit when connection is made therewith, means at the trunk circuit for controlling the latter supervisory relay, and a common signal controlled by said relays.

7. A telephone system comprising magneto and common battery lines, a cord circuit connected to a magneto line, a trunk circuit adapted for interconnecting said cord circuit and a common battery line, a pair of talking conductors included in the connection extending between said cord and trunk, a supervisory relay for the cord circuit,a guard signal relay for the trunk circuit, a se ries energizing circuit for said relays including a third conductor between said cord and trunk and closed upon connection made between said cord and trunk, a signal for the cord responsive to the energization of-its supervisory relay, a guard lamp and circuit adapted to be closed by said guard relay if said cordand trunk are connected before said trunk is connected to the common battery line, and means at the trunk circuit for interrupting said series circuit to dencrgize the supervisory relay and signal, said means being controlled over the common battery line.

8. A cord circuit comprising a pair of talking conductors connecting the answering and calling ends thereof, a magnet winding in bridge of each end thereof, a locking armature and contact for each magnet rendered eliective responsive to said magnet, a supervisory signal for each magnet controlled through the associated contact, a restoring magnet for each locking contact, energizing circuits for said restoring magnets controlled by an operators key, and branch conductors from the last said circuits extending to a third conductor terminating at each end of the cord circuit.

Signed by me at Chicago, county of Cook, and State of Illinois, in the presence of two witnesses.

CHARLES S. WINSTON. 

